This invention relates generally to automotive vehicle door locks and more particularly to a door lock actuator that may be used in electrically actuated door locks commonly referred to as power door locks.
Automotive vehicles have a door latch on each vehicle door to latch the door in the closed position. Each vehicle door latch includes a lock that is commonly actuated from inside the vehicle by a readily accessible sill button or other manually operable device on the door. The vehicle door lock for the front doors is conventionally operated from outside the vehicle as well usually by a key lock cylinder that has a removable key to deter theft.
Upscale automotive vehicles commonly employ a power lock system as a convenience feature. The power lock system commonly employs an electrically powered actuator associated with each door latch (and sometimes also with the trunk latch and fuel filler door latch) to move the door lock between its locked and unlocked positions. The actuators are controlled in a variety of ways. In the so called American system, all the actuators are controlled by any one of three switches. These three switches are located in the key lock cylinder for the driver's door and on the interior trim panel for each front door. Thus all doors can be locked or unlocked from outside the vehicle by means of the key lock cylinder switch in the driver's door or from inside the vehicle by means of the switches next to the driver or the front seat passenger.
Manual and power door lock systems have a common problem. As indicated above, the front door locks are commonly actuated from outside the vehicle by a key lock cylinder that has a removable key to deter theft. In four door vehicles, the rear door locks cannot be unlocked from outside the vehicle. However, the door lock for any door is commonly actuated from inside the vehicle by a readily accessible sill button or other manually operable device that does not have any theft deterrent feature. Consequently, the theft deterrent aspect of the key operated door lock can be circumvented by breaking a vehicle window, reaching inside the vehicle and unlocking the vehicle door by means of one of the inside sill buttons or its equivalent.
To overcome this circumvention technique, the superlock feature has been developed as a counter measure in the case of power door lock systems. Briefly this superlock feature is a system that is operated by the key lock cylinder in the driver's door. The superlock system comprises a superlock position in the drivers key lock cylinder, a mechanical block out for the inside sill button or its equivalent in the driver's door and superlock positions in the actuators for the remaining doors that disable the inside sill buttons for these other doors. See for instance U.S. Pat. Nos. 4,342,209; 4,364,249; 4,440,006 and 4,727,301.
One disadvantage of a known superlock system is that it requires sequential operation to insure that all door latches are locked because if one door latch is unlocked by the sill button, the actuator for that door latch does not lock the door latch when it is actuated. Consequently the control switch must always be moved to the unlock position first and then to the lock position to insure that all door latches are locked. Such sequential operation systems are not favored by convenience oriented customers; particularly in North America.
Another disadvantage of another known superlock system is that it requires an extra electric motor in each actuator to engage and disengage the superlock mode. This adds considerable expense to the door lock actuator and the superlock system.